Term bank reserves Definition: The "money" that banks use to conduct day-to-day business, including cashing checks, satisfying customers's withdrawals, and clearing checks between accounts at different banks. The "money" in question includes vault cash and Federal Reserve deposits. Specifically, vault cash is the paper money and coins that a bank keeps on the bank premises (both in the vault and in teller drawers), which is used to "cash" checks and otherwise provide the funds that customers withdraw. Federal Reserve deposits are accounts that banks keep with the Federal Reserve System, which are used to process, in a systematic, centralized fashion, the millions of checks written each day by customers of one bank that are deposited by customers of another bank. Using these deposits, the Fed acts as a central clearing house for checks, being able to simultaneously debit the account of one bank and credit the account of another. More on the importance of bank reserves can be found under fractional-reserve banking.